<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>03</title>
</head>
<style>
    .box{
        width: 300px;
        height: 200px;
        border: 1px solid #333;
        margin: 10px auto;
    }
    .box>div{
        float: left;
        margin: 29px 15px;
        width: 30px;
        height: 100px;
        border-radius: 15px;
        animation: fang 500ms linear  infinite alternate;
        
    }
    .box>div:nth-child(1){
        background-color: red;
        animation-delay: 100ms;
    }
    .box>div:nth-child(2){
        background-color: green;
        animation-delay: 200ms;
    }
    .box>div:nth-child(3){
        background-color:blue;
        animation-delay: 300ms;
    }
    .box>div:nth-child(4){
        background-color: yellow;
        animation-delay: 400ms;
    }
    .box>div:nth-child(5){
        background-color: pink;
        animation-delay: 500ms;
    }
    @keyframes fang{
        form{
            transform: scale(1,1);
        }
        to{
            transform: scale(1,0.5);
        }
    }
    p{
        text-align: center;
    }
</style>
<body>
    <div class="box">
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <div></div>
        <p>londing...</p>
    </div>
</body>
</html>